The Modern Gardener’s Bestie
Our dear friend, Dave Hunter from Crown Bees, stopped by and we were able to chat about all things leafcutter bees. Leafcutter bees are super pollinators and just like mason bees, leafcutters carry pollen on their furry abdomens. They both are in the family of large jawed bees, Megachilidae.
Some people like to refer to them as nature’s hole punch – these bees will use perfect discs of petals or leaves to build leafy chambers that protect their eggs, and to seal their nests from predators. If you happen to see a leaf or petal in your garden with an almost perfect circle or oval cut from it, you know that you have a healthy pollinator community nearby, and that’s a good thing!
Active from early June through to September, leafcutters work at a rapid rate and for those of us growing food, leafcutters are ideal. Flying only a few hundred feet from their nesting grounds, they stay close ensuring that your veggies and flowers are being pollinated. A well pollinated flower produces fruit that is fuller, larger and often tastier than others. As garden guests they are great for families with kids and pets; leafcutters are gentle, small and a ton of fun to watch as they bounce from plant to plant.
Dave is Woodinville’s resident bee expert. If you’re considering raising leafcutter bees read our interview with Dave and be sure to come shop leafcutter supplies right here at Molbak’s.
Why should both novice and expert gardeners care about leafcutter bees in the PNW?
Dave Hunter: Ultimately it all comes down to pollination. Solitary bees like mason and leafcutter bees pollinate around 95% of the flowers they visit, whereas honey bees generally only pollinate about 5% of the flowers they visit. These prolific pollinators are a bit sloppy compared to other species and I mean “sloppy” in the most endearing way. Females carry pollen on the underside of their abdomens rather than their hind legs, like the honeybee. This means that the pollen falls off easily and every plant they visit is dusted with pollen. You can spot a bee that’s been busy foraging because their bellies will be yellow to gold in color.
At a time when many pollinator species are at risk, we should welcome bees to our gardens and provide them with the food and shelter they require to perform such an important role. The presence of leafcutters is an indicator that you have a healthy garden on your hands.
What are some common misconceptions people have about these bees?
One of the biggest misconceptions is that leafcutter bees harm plants. The minor cuts the leafcutter bees make in the leaves do not harm the plants! Bees and flowering plants have evolved together for millions of years! It's a mutual relationship, where the bees get food and nesting materials from the plant, and in return, the plant uses the bee to carry its pollen to other plants of the same species, or pollination!
Some people find the cuts unsightly to look at, but we prefer to think of them as evidence of pollination in action and a sign of a healthy ecosystem. Plus, it's a great conversation starter at your next BBQ! I release thousands of leafcutters around my home each year and it’s still hard to spot a leaf that’s been punched by a leafcutter. Unlike other insects that feed on our beloved plants, leafcutters only take what they need.
These bees are also very gentle. Unlike other species, they don’t attack when their nests are approached. When handled you may get stung, but it is pretty painless. The lesson here is don’t try to pet a leafcutter and you won’t get stung.
How can you identify a leafcutter?
- Native Megachile bees vary in size, on average they’re about the same size as a honeybee. However, the alfalfa leafcutter bees that you can buy through Crown Bees are slightly smaller than the honey bee.
- Leafcutter bees are dark in color with light bands on their abdomen. Females have black eyes, while males have green eyes.
- Leafcutter bees have large scissor-like jaws to cut and gather leaves, flower petals, and resin to construct their nests.
- All female leafcutter bees have parallel rows of pollen-collecting hairs, called the scopa, on the underside of their abdomen. When a bee is carrying pollen, the underside of the abdomen appears yellow or gold in color. Only female leafcutter bees have a scopa. Males do not help transport pollen back to the nest and do not need these specialized hairs.
How do you prepare to raise leafcutter bees?
Our team has created a guide for raising leafcutters that you can find here. In an effort to get your garden leafcutter ready consider this checklist:
- Does my garden contain the proper plant material? Think soft, flexible leaves and flower petals.
- Are there open blooms within 300 feet from where the bee house is installed?
- Are daytime temps at least 75°F?
- Is the bee house in a protected location with morning sun?
- Is my garden and yard free from chemicals?
What plants attract leafcutters?
Leafcutter bees often use the leaves of broadleaf, deciduous plants to build their homes. If you’re looking to attract these super pollinators to your garden I recommend plants with non-hairy, soft, flexible leaves and petals.
Nest building:
- Alfalfa
- Clover
- Buckwheat
- Roses
- Lamb’s Quarters
- Lilac
- Redbud trees
- Hostas
- Azaleas
- Bougainvillea
- Black-eyed Susan
- Clematis
Fruit & Veg:
- Squash
- Melons
- Peas
- Tomatoes
- Carrots
- Blueberries
- Mint
- Beans
- Onions
Native Plants:
- Gumweed
- Goldenrod
- Western Azalea
- Douglas Asters (foraging)
- Washington coneflower (foraging)
- Cascade penstemon
- Campanula AKA tall bellflower
Plants for Foraging:
- Cosmos
- Clematis leaves
- Dahlias
- Sunflowers
- Mint / Salvia
If you’re looking to introduce leafcutter bees to your outdoor space, Molbak’s carries Crown Bees houses, nesting trays, tubes and accessories to get you started.
